Chen Yiyang, Qiu Yuanxin, Lew Matthew D
Washington University in St. Louis, Preston M. Green Department of Electrical and Systems Engineering, Missouri 63130, USA.
Phys Rev Lett. 2025 Mar 7;134(9):093805. doi: 10.1103/PhysRevLett.134.093805.
We prove that it is impossible to distinguish two spatially coinciding fluorescent molecules from a single rotating molecule using polarization-sensitive imaging, even if one modulates the polarization of the illumination or the detection dipole-spread function (DSF). If the target is known to be a dipole pair, existing imaging methods perform poorly for measuring their angular separation. We propose simultaneously modulating the excitation polarization and DSF, which demonstrates robust discrimination between dipole pairs versus single molecules. Our method improves the precision of measuring centroid orientation by 50% and angular separation by two- to four-fold over existing techniques.
我们证明，即使调制照明偏振或检测偶极子扩展函数（DSF），也不可能使用偏振敏感成像从单个旋转分子中区分出两个空间重合的荧光分子。如果已知目标是一个偶极子对，现有的成像方法在测量它们的角间距时表现不佳。我们提出同时调制激发偏振和DSF，这证明了在偶极子对与单分子之间具有强大的区分能力。与现有技术相比，我们的方法将测量质心方向的精度提高了50%，将角间距测量精度提高了两到四倍。
